TEHRAN (AFP) - A top Iranian cleric accused Pakistan on Friday of becoming a "terrorist sanctuary," following an upsurge of violence on the two nations' border area that Tehran blames on plots by arch foe the United States and on Pakistan's inability to control its border.

"Though Pakistan is our neighbour, little by little it is losing its neighbourly manners. Pakistan has become a sanctuary of terrorists who kill people in Zahedan," hardline cleric Hojatoleslam Ahmad Khatami told Friday worshippers in Tehran.

Zahedan is the capital of the southeastern province of Sistan-Baluchestan, which is home to a population of minority Baluch Sunni Muslims. It borders Pakistan to the south and
Afghanistan to the north.

Thirteen Revolutionary Guards were killed last month when militants set off a car bomb in Zahedan, and security forces also clashed with militants in the city when a percussion bomb exploded.

And on Tuesday, four policemen were killed, one abducted and another wounded in Sistan-Baluchestan by rebels who then allegedly fled towards Pakistan.

"Pakistan should be careful not to fall into the US trap, since it will be the loser, undoubtedly," Khatami added in a sermon broadcast live on state radio.

"Iran is a strong country. Certainly being
Iran's friend is much better than being the US and
Israel's friend. There is no benefit in being the US and Israel's friend," he said to the habitual chants of "death to America, and death to Israel."

Iran summoned Pakistan's ambassador after the unrest last month and both sides agreed to reinforce border security.